1. Technical Field
The present invention relates to a reflective screen.
2. Related Art
As a screen on which a projected image is displayed, there have been a variety of proposed screens that suppress decrease in contrast of the projected image due to external light from a fluorescent lamp or any other light source in conference rooms, school classrooms, and other bright room environments (see JP-A-2006-215162, for example).
The screen described in JP-A-2006-215162 has a plurality of convexly curved portions (hereinafter referred to as unit shaped portions) regularly disposed two-dimensionally on a projection surface. A reflection surface is formed on each of the unit shaped portions only in part of the surface thereof that faces incident image light.
In the configuration described above, the image light originating from a projector and incident on the screen obliquely upward is reflected off the reflection surface in each of the plurality of unit shaped portions, directed toward a side where a viewer visibly recognizes the image light. The viewer thus recognizes the image light as a projected image.
On the other hand, external light originating from the fluorescent lamp or any other light source and incident on the screen obliquely downward is not incident on the reflection surface in each of the plurality of unit shaped portions but is incident on and absorbed by the portion other than the reflection surface. That is, the external light will not be reflected off the screen toward the side where the viewer visibly recognizes the image light.
A screen that suppresses decrease in contrast, such as the screen described in JP-A-2006-215162, has a preset field of view across which a projected image can be visually recognized.
The tradeoff for a greater size of the field of view will be lower brightness of the projected image to be visually recognized. For example, the field of view needs to be narrowed in order to provide sufficient brightness of the projected image.
That is, when the size of the field of view is narrowed in order to provide sufficient brightness of the projected image, a problem occurs, for example, in a presentation. Specifically, a presenter tends to have difficulty in visually recognizing the projected image when the presenter stands close to the projection surface because the presenter who looks at the screen is outside the preset field of view. An audience outside the field of view also has difficulty in visually recognizing the projected image.
To make the projected image visually recognizable even in the situation described above, it is conceivable to simply enlarge the field of view, but the brightness of the projected image disadvantageously decreases as described above.